1. Field of the Invention
The present invention relates to an apparatus for testing a plurality of fluid samples at elevated temperatures and/or pressures, while providing for simultaneous stirring of said samples to simulate desired fluid flow regimes. More specifically, the present invention relates to a temperature controlled enclosure containing multiple synchronized magnetic stirring assemblies which allow for synchronized stirring and simultaneous thermostating of one or more pressurized sample cells containing fluid samples to be tested.
2. Description of Related Art
Stirring apparatuses have been known in the art for some time. One recent example is disclosed in U.S. Pat. No. 5,547,280 to Wanninger et al., which describes a magnetic stirrer wherein a drive motor with controlling means and an electrical connection are placed in a lower part, and a glass mounting surface, which is largely impervious to aggressive liquids and vapors, comprises a top part. Said top part forms a mounting surface for a stirring container which holds a stirring magnet. The invention disclosed in Wanninger, et al, is easily distinguishable from the invention disclosed herein because it has no means to control the temperature of the samples to be tested.
An apparatus with a temperature control device is disclosed in U.S. Pat. No. 4,876,069 to Jochimsen. The Jochimsen patent discloses a blood clotting time measuring apparatus having a temperature controlled cabinet with at least one measuring port for receiving sample cells containing blood. A magnetic stirrer is mounted in the cabinet proximate to the measuring port to enable stirring of a metal ball placed inside the sample cell. However, unlike the invention disclosed herein, the Jochimsen patent does not disclose means for enclosing the entire sample to be tested. Furthermore, the Jochimsen patent does not disclose means to analyze the subject sample at elevated pressures, and envisions use of relatively small-volume samples.
Another magnetic stirring device with a temperature control mechanism is disclosed in U.S. Pat. No. 5,529,391 to Kindman, et al. The invention disclosed in Kindman relates to a magnetic stirring and heating/cooling apparatus that provides simultaneous stirring and thermostating of multiple, yet relatively small, biological samples. The apparatus disclosed in Kindman utilizes a heat conducting block which provides thermostatic temperature control. Liquid samples contained in vessels can be inserted into multiple sample wells which are bored into said heat conducting block. Multiple coils surround the lower portion of each of the multiple sample wells to provide rotating magnetic fields that motivate magnetic stirring bars which are positioned inside the sample vessels. Unlike the invention disclosed herein, the Kindman patent does not disclose means for applying pressure to the samples being tested.
Other patents of interest which disclose magnetic stirrers include U.S. Pat. No. 3,784,170 to Petersen et al.; U.S. Pat. No. 4,991,973 to Maaz et al.; U.S. Pat. No. 4,752,138 to Rufer; U.S. Pat. No. 4,759,635 to MacMichael et al.; and U.S. Pat. No. 4,830,511 to Smazik. However, none of these references disclose applicant's novel inventive apparatus which provides for simultaneous synchronized stirring and thermostating of multiple samples contained in pressurized sample cells.